1. Field of the Invention
This invention relates to the fabrication of stabilizer ply members in the construction of a tire and more particularly to the means and method for trimming the stabilizer plies in order to produce a highly uniform stabilizer ply construction which results in a high degree of durability which provides for an improved tire. Specifically, the instant invention relates to a trimming means and method used in conjunction with an automated tire assembly system which automatically trims the edges of the stabilizer ply member. The instant invention employs a rotary cutter angled with respect to the axis of the stabilizer ply member in order to produce a uniform cut and which is adapted to be used in conjunction with automated tire assembly equipment.
2. Description of the Prior Art
Means for the trimming of stabilizer ply members are old in the art and include means employing rotary trimmers. Conventionally, rotary trimmers are used in connection with a manual tire assembly machine in order to trim the stabilizer ply members after they have been manually applied to the building drum of the tire assembly machine. In a typical arrangement the stabilizer ply trimmers are located below the building drum and are mounted in order to be movable along the axis of the tire building drum. When it is desired to trim the stabilizer ply members, the trimmer means are moved in order to cause one of the rotary trimmers to engage one of the edges of the stabilizer ply member. When the cut of the first edge of the stabilizer ply member has been completed, and the rotational direction of the drum is reversed, the trimmer means is caused to engage a second rotary trimmer with the opposite edge of the stabilizer ply member in order to cause the trimming of that edge of the stabilizer ply member. In both instances the plane of the rotary cutter of the stabilizer ply trimmer is orthogonal to the axis of the building drum of the tire assembly machine.
One of the problems encountered in the prior art is an irregularity produced in the edge of the trimmed stabilizer ply member caused by the failure of the rotary trimmer to correctly cut the stabilizer ply member during the time it is caused to engage the edge of the stabilizer ply member. Due to the flexible nature of the edge of the stabilizer ply member, during the initial plunge of the rotary trimmer into the stabilizer material, the stabilizer ply material is slightly deflected thereby preventing the rotary trimmer from properly cutting the stabilizer ply material. This results in a slight hump at the position where the rotary trimmer is introduced into the stabilizer ply member.
A second problem encountered with the prior art concerns the minimum width of cut that must be taken in order to produce an acceptable cut by the rotary trimmer. It has been experienced that it is necessary to cut at least 3/16 inch (4.7 mm) of stock from the edge of the stabilizer ply member in order to produce an acceptable quality of cut and thereby produce a desired uniform edge of the stabilizer ply member. It has been found that any attempts to produce a cut of lesser width results in an irregular cutting action of the rotary trimmer and hence an irregular edge of the stabilizer ply member. The requirement for cutting a relatively large portion from the stabilizer ply means results in a substantial amount of stabilizer ply stock being discarded as scrap with the subsequent increase in costs in the manufacture of the stabilizer ply means.
A third problem associated with the prior art means of trimming the stabilizer ply means concerns the removal of the cut salvage from the stabilizer ply member. Due to the tacky nature of the stabilizer ply material, there is a tendency for the cut salvage of the stabilizer ply material to re-attach itself to the edge from which it was cut after passing by the knife of the rotary cutter. In the conventional situation where the rotary trimmers are utilized in conjunction with a manual tire assembly machine, the re-attachment of the cut salvage to the stabilizer ply member is eliminated by having the operator manually pull the cut salvage from the stabilizer ply member after it has been cut by the rotary trimmer. This means for salvage removal is totally unsuitable for use in connection with an automated tire assembly system.
There is, therefore, a need for an apparatus which is readily adapted to trim the edges of a stabilizer ply member without deforming the edge thereof in order to produce a uniform cut and which may efficiently cut the edge of the stabilizer ply member with only a relatively small salvage and further having means for the removal of the salvage from the edge of the stabilizer ply member which facilitates use in conjunction with automated tire assembly equipment. The instant invention provides such a means allowing for the precise cutting of the edges of a stabilizer ply member wherein a relatively small salvage may be cut from the edge of the stabilizer ply assembly and the salvage is automatically removed from the edge of the stabilizer ply assembly.